Semiconductor devices are used in many electronic and other applications. Semiconductor devices comprise integrated circuits or discrete devices that are formed on semiconductor wafers by depositing many types of thin films of material over the semiconductor wafers, and patterning the thin films of material to form the integrated circuits.
The semiconductor devices are typically packaged within a ceramic or a plastic body to protect from physical damage and corrosion. The packaging also supports the electrical contacts required to connect to the devices. Many different types of packaging are available depending on the type and the intended use of the die being packaged. Typical packaging, e.g., dimensions of the package, pin count, may comply with open standards such as from Joint Electron Devices Engineering Council (JEDEC). Packaging may also be referred as semiconductor device assembly or simply assembly.
Packaging may be a cost intensive process because of the complexity of connecting multiple electrical connections to external pads while protecting these electrical connections and the underlying chips.
Packaged devices are mounted on a printed circuit board or other equivalent component for connecting with other components. In many applications, space on a printed circuit board or within a final device (e.g., a hand held device) is limited. Therefore, in some designs, the packages are stacked over each other. However, vertical stacking may not be sufficient when the components have to be packed within a limited space. Alternatively, vertically stacked dies within a single package are expensive due to the more complex packaging process and have to be predesigned and therefore provide no flexibility to the consumer.